In recent years, a recording system for recording and playing music data that is, for example, retrieved from Compact Disc (registered trademark) and stored on a hard disk drive or the like is provided for sale in a market. The recording system on this kind is typically installed as a navigation system or a audio system on a vehicle.
Some of the recording systems described above are capable of, for example, recording and playing the music data at the same time for accommodating user's needs on the vehicle. The recording system usually records the music data in a PCM format by reading it faster than a playback speed (e.g., a double (2×) speed, a 4× speed or the like in comparison with the playback speed) for reducing the recording time.
However, the increased recording speed (i.e., the reading speed) of the recording system tends to cause a recording error during recording of the music data. One of the cause of the recording error is a vibration of the vehicle. That is, the increased recording speed forces a CD drive or the hard disk drive to operate at an increased speed, thereby causing an unstableness in reading/recording operation when the vibration of the vehicle is added thereto. As a result, the recording system suffers from the recording error during the recording of the music data in the increased recording speed. The recording error is especially problematic when the recording system is used as a part of the navigation system/audio system on the vehicle where the navigation/audio system are typically exposed to a severe vibration during its operation.
In addition, the navigation system may try to access the hard disk drive for retrieving required data such as map data or the like at the same time when the audio system is playing back the music data. When the hard disk drive is in demand for access from plural systems, one of the access may be blocked by the other access. That is, in this case, the access to the hard disk drive from the audio system for recording the music data is occasionally blocked by the access from the navigation system. As a result, the recording of the music data at the increased speed is aborted as the recording error.
Chances of the recording error can be reduced by decreasing the recording speed. However, the user's needs for reducing the recording time is compromised.
The Japanese patent document No. JP-A-2001-210009 discloses an error handling process during a dubbing operation (i.e., a recording operation) of the CD music data. In this disclosure, a dubbing system goes back to a start point of a recording track and restarts the dubbing operation at a reduced dubbing speed when an error is detected during the dubbing operation at an increased dubbing speed.
However, the error handling process described above is problematic for handing the error in the recording and reading operations conducted at the same time in the following aspect. That is, the playback of the music data of the recording track returns to the start point of the recording track when data retrieval position returns to the start point of the recording track due to the recording error. The jumpiness of the playback of the music data makes the user feel uncomfortable.
The problem described above may also be experienced when the hard disk drive is involved in recording movie data while it is being played back. That is, the movie data of the recording track may suffer from dropping frames due to the recording error when the data is being played back at the same time with recording.